Metal window



May 9, i951 J. A. GILLIGAN ET Ax. 2,983,344

METAL WINDOW Filed Aug. 6, 1959 /A/vEn/ro/es f; JOHN A. G/LL/GA/v and @5E/PHAR@ HAA/JER By @ww/ MEL Affnrney States aten-t Patented May 9, 1961 ice METAL WINDOW John A. Gilligan, Mount Lebanon Township, Allegheny County, and Geerhard Haajer, Wilkins Township, Allegheny County, Pa., assignors to United States Steel Corporation, a corporation of New Jersey Filed Aug. 6, 1959, Ser. No. 832,014

1 Claim. (Cl. 189-78) This invention relates to a metal window and, in particular to a window the sash and frame of which are composed of tubular rails formed up from sheet metal.

rl`he object of our invention is to provide a window of the type described which can be made of material of lighter gage than it has heretofore-been possible to use, thereby reducing the cost and weight of the window, yet yat the same time maintaining the strength and rigidity of the completed structure necessary to withstand service loads with a reasonable safety factor.

Windows having sash and frame composed of tubular rails formed from sheet metal have been known heretofore but the rails were of generally rectangular section shaped to simulate solid wood members and were welded at the corner joints. They accordingly had to be made of relatively heavy-gage material and required special finishing to remove the visible evidence of the welds. We have invented a window including a sash composed of tubular rails of novel section which can be made of rela- Ktively thin gage sheet and still exhibit adequate strength and rigidity for any normal application. We connect the rails at the corner joints by inserted brackets mechanically secured thereto.

A complete understanding of the invention may be obtained from the following detailed description and explanation which refer to the accompanying drawings illustrating the present lpreferred embodiment. In the drawings:

Figure l is an elevation of our improved window, including frame and sash; and

Figure 2 is a partial section taken along the plane of line ll-Il of Figure l.

Referring new in detail to the' drawings, the window 10 of our invention comprises a rectangular frame 11 and a rectangular sash 12 positioned therein carrying a pane 13. The sash may be iixed or pivoted, projected or hopper type. In the illustrated embodiment it is pivoted on a vertical axis by trunnions 14. The frame 11 is composed of four rails, a sill 15, a transom 16 and stiles 17, all tubular and rectangular in section as shown in Figure 2, formed by bending at sheet metal, e.g., stainless-steel sheet. The rails are joined at the corners by angle brackets 18 fitting snugly therein and secured thereto by a suitable adhesive such as an epoxy resin. The inner face of the frame rails has spaced ilats 19 with a channel 20 recessed between them to accommodate the bearings for trunnions 14.

Sash 12 is composed of four rails, bottom, top and side, designated 21, 22 and 23, respectively. These rails are tubular in section and formed by bending up ilat sheet metal such as stainless-steel sheet. Each rail comprises a generally at web or outer strip 24 having its edges hanged outwardly as at 25 and an inwardly recessed central longitudinal channel 26. Between the anges and channel, strip 24 is deformed to provide longitudinal grooves 27. Sealing gaskets 28 extruded from rubberlike material are seated in grooves 27 and each has a web or tin that wipes surfaces 19 of thefname rail to close the joint between sash and frame. Blocks 39 on which trunnions 1-4 are formed are seated in channels 26 and the trunnions are journaled in similar blocks 40 seated in channels 20. Back-up blocks 41 and 42 are located in the sash and frame rails opposite blocks 39 and 40.

The remainder of the sash rails is constituted by a paneseating member 29 and a keeper member 30, together forming an 'arch springing from the edges of strip 24 with a central channel 31. One edge of member 29 is lock-seamed to one of the Ilianges 25 and extends nwardly on a smooth curve as at 32. The member 29 also includes one side and the bottom of channel 31. Thence, the metal sheet of which the member is formed extends obliquely as at 33 to the other edge of strip 24 and is lock-seamed thereto. Intermediate the bottom of channel 31 and flange 25, the metal forming member 29 is oiset to alord a ledge 33a.

Keeper member 30 has its outer edge shaped as at 34 to fit over the lock-seam uniting strip 24 and oblique portion 33 of member 29. Thence member 30 extends inwardly on a smooth curve designated 32 and is' bent outwardly to form the other side wall of channel 31. An inner edge of flange 35 on keeper member 30 bears tlatwise against oblique portion 33 of member 29 and seats against ledge 33a thereof. The keeper members; are removably secured to the pane-seating members by screws 36. Sash rails 21, 22 and 23 are connected at the corners of the sash by angle brackets 37 fitting snugly in the paneseating members and secured thereto by an epoxy-resin adhesive.

The glass pane 13 has its edges provided with a cushioning and sealing channel 38 of rubber-like material and is installed in the pane-seating members of the sash by removing the keeper members. Replacement of the latter after setting the glass constitutes the whole a strong, Weather-tight and rigid structure. The frame 11 may be set in a wall opening prepared therefor and fixed therein in the known manner with calking as necessary to seal the joints between the frame and wall.

Our construction makes possible a window having a stiffness ratio which, when the Window is supported at the midpoints of its four sides, aiords maximum resistance to wind load and minimum deection thereunder at the corners. This ratio may be defined as EI/LD where:

E=modulus of elasticity of the material of which the sash rails are made;

I=moment of inertia of the combination of sash members 24 and 29; the moment of inertia being taken about an axis passing through the centroid of the combination of sash members 24 and 29, the axis being perpendicular to the plane forming the bottom of chan- =ne131.

L=height or Width of window, whichever is greater;

D=-.1Egt3/12(1-n2) :plate-bending stiffness of pane of g ass;

Eg=modulus of elasticity of glass;

t=thickness of pane of glass; and

,u=Poissons ratio for glass.

For best results, EI/LD should be between l and 3. In a typical construction, viz., a window six feet high having sash nails about 1" x 2 and glass pane 1/1 thick, the value of this ratio is about 2.0.

The advantage of our invention is that it permits windows'to be made of lighter sheet (e.g., .025" thick) and yet retain adequate strength and rigidity. Thus, we realize a substantial-reduction in both the weight and cost of la metal window as compared with those known heretofore.

While the window of our invention has been disclosed as having a fully reversible, vertically pivoted sash, the same principle may be applied to windows having fixed s sash and projected or hopper sash. In any case, the sash may be double-glazed as Well las of the single-glazed type shown.

Although we have disclosed herein the preferred ,embodiment of our invention, we intend to cover as well any change or modiication therein which may be made without departing from the spirit and scope of the invention.

We claim:

A Window sash composed of tubular rails formed from sheet metal, each rail comprising an outer generally at strip having outwardly turned anges at its edges, a pane-seating member inwardly of said strip and cooperating therewith having its edges lock-seamed to said anges `and a keeper member secured to said pane-seating member, said pane-seating member and keeper member both including arch segments springing from said anges vand terminating in outward anges which together de- -flne a pane-receiving channel therebetween, said paneseating member also having a bearing surface engaged by said keeper member and said keeper member having a flange iat its outer edge engaging t'ne adjacent joint between said strip and said pane-seating member.

References Cited in the le of this patent UNITED STATES PATENTS 977,415 Matthews Nov. 29, 191() 1,170,917 Lund Feb. 8, 1916 2,733,788 Farmer Feb. 7, 1956 2,811,754 Toth Nov. 5, 1957 2,812,557 Hauck Nov. l2, 1957 

